Tool sharpening apparatus

ABSTRACT

The invention relates to apparatus for use in the sharpening of tools and in particular to apparatus for the sharpening of selected ones of a plurality of different tools, said apparatus including a grinding wheel and a plurality of tool holders. At least one of the tool holders is connected to the apparatus so as to be movable between out-of-use and in-use positions thereby allowing the cool holder to be positioned accurately. In one embodiment the housing is provided on a base which is provided with storage means for other sharpening implements and/or accessories.

The invention to which this application relates is apparatus to be usedto allow for the sharpening of blades or cutting edges of a plurality oftools and with the apparatus being adaptable to allow particularsharpening means to be available for use with respect to particulartools.

Although the following description refers almost exclusively to use ofhingedly connected adaptors for presenting tools to a grinding wheel, itwill be appreciated by persons skilled in the art that adaptors could berotatably mounted or connected in alternative ways to secure the same.

The provision of apparatus which allows the sharpening of blades oftools is well known. Typically, the apparatus comprises a rotatinggrinding wheel which has a coating of abrasive material thereon. Theparticular abrasive material which is selected can be from any of arange of known materials to suit particular quality and/or practicalrequirements.

The wheel is provided to rotate, typically driven by a motor and thereis provided at least one adaptor which can be presented to a surface orsurfaces of a grinding wheel and into which the blade to be sharpened isfitted such that when the adaptor is presented to the grinding wheel,the blade in the adaptor is presented to the grinding wheel at anappropriate orientation to facilitate the sharpening of the blade by theremoval of material from the blade to leave an edge of requited shape.The tools which can be sharpened include drill bits, knife blades,scissor blades, chisel blades or the like and typically, a series ofdifferent adaptors are requited to be provided for each or each group oftools so as to ensure that said tools are respectively presented to thegrinding wheel at the appropriate orientation for the particularsharpening requirement.

It is known to provide a series of adaptors, each of which can belocated with respect to the grinding wheel either by screwing theadaptors in position to thereby provide the most effective and securelocation of the adaptor in position or, alternatively, by providing anautomatic latching means which allows the adaptor to be slid intoengagement means and latched in position with respect to the grindingwheel and a housing in which the grinding wheel is provided. Inpractical terms however, a problem is experienced with the automaticlatching means in that the tolerances of the manufacture of the adaptorand/or housing means that the adaptors can move to a limited degree withrespect to the housing and hence the grinding wheel thereby causinginferior sharpening to be achieved on the blade held in the adaptor.

The aim of the present invention is to provide apparatus which allowsfor the selective sharpening of blades of different tools by providing aseries of adaptors which can be selectively positioned with respect to agrinding wheel and secured in the required position so as to present thetool at the required orientation to the grinding wheel.

In a first aspect of the invention there is provided Apparatus for thesharpening of a blade or cutting edge of a tool, said apparatusincluding a rotatable grinding wheel, a motor connected to said grindingwheel, and a plurality of tool holders, at least one of which is movablebetween an out of use position and an in-use position with respect tothe grinding wheel and, in the in-use position, the said at least onetool holder provides a location for a tool to be in the appropriateposition such that an edge or point of said tool can be sharpened incontact with said grinding wheel and wherein said at least one toolholder is attached to a base and/or housing in which the motor andgrinding wheel are provided, said connection retained in both in-use andout-of-use positions, and when moved between said positions.

In one embodiment, the tool holders can be secured by securing means inthe in-use position and/or out-of-use position with respect to thehousing.

In one embodiment, the securing means is any or any combination ofscrews, nuts, catches, latches, clips, grips, magnets, springs and/orthe like.

In one embodiment the securing means is mounted on the housing.Typically the securing means passes through an aperture in the toolholder and is actuated to secure the same.

In a preferred embodiment, a plurality of the tool holders are hingedlyconnected with respect to the housing and/or base such that the same areindependently moved to the in-use position, and in one embodiment thesame move over centre so that the effect of gravity on the holder actsto bring the holder into contact with the housing thereby aiding theability for the tool holder to be kept in a fixed position with respectto the housing during use. It will be appreciated that the tool holderscould otherwise be rotatably mounted to achieve a similar effect.

In one embodiment, a plurality of tool holders are provided forsharpening blades of tools each hinged with respect to the housing sothat each is hingedly moved to a respective side of the said housing.

In one embodiment, at any given time, one of the tool holders can beselectively moved to an in-use position for use of the apparatus forsharpening a tool held thereon. In another embodiment, a plurality ofthe tool holders can be moved to an in-use position and used forsharpening tools which are held in the respective tool holder by theuser and/or fixing means.

In one embodiment, further tool holders are provided in the form of oneor more access ports and/or notches provided on the housing to allowtools to be sharpened by application to the grinding wheel therethrough.

Typically the tool holders are designed to hold any or any combinationof scissors, blades, knives, chisels, screwdrivers, drill bits, and/orthe like.

Typically each of the tool holders includes a suitable locationformation to allow a tool to be held in or on the tool holder and at asuitable orientation to the grinding wheel for sharpening.

In one embodiment adjustment means are provided to allow the grindingwheel to be adjusted in height with respect to the housing, to take intoaccount wear of the same. Typically the adjustment means is located onthe underside of the device, and adjusts the height of the motor withinthe device, thereby adjusting the height of the wheel connected thereto.

Typically the housing can be secured to a base in the form of a trayand/or a supporting surface. Typically the tray is provided with astorage means for storing accessories. In one embodiment storage meansinclude any or any combination of a lid, recesses, drawers and/or thelike. Typically the accessories include any or any combination of drillbits, grinding wheels, finishing stones, spanners, a water bath,cleaning brushes, safety glasses, and/or the like.

In one embodiment the apparatus base includes an area for the collectionof liquid to be used during the sharpening process.

The base can also include storage for additional grinding wheels whichmay be straight replacement wheels or may have different grinding orsharpening characteristics and thereby allow the same to be selectivelyfitted and used for specific sharpening processes. In one embodiment theapparatus includes a carborundum finishing stone.

In one embodiment the grinding wheel can be reversibly mounted withrespect to a shaft leading from the motor so as to allow full use of thegrinding wheel to be achieved and any wear of the same to be taken intoaccount.

Typically the grinding wheel is mounted with respect to the motor so asto have a substantially vertical axis of rotation.

In one embodiment the housing includes a notched section to allow forthe passage of a drill bit therethrough to be applied to the grindingwheel for sharpening. In this arrangement the drill bit is held in achuck which is positionable with respect to the housing.

In one embodiment retention means are provided to allow the tool holdersto be retained in an out of use position.

In one embodiment the apparatus includes a base on which the housing ismounted, and a lid which is engageable with the base and movable betweena closed storage position and a partially open guard position to protectthe user of the apparatus from sparks or other debris from the grindingprocess.

In a further aspect of the invention there is provided apparatus forallowing the sharpening of a blade or cutting edge of a tool, saidapparatus including a rotatable grinding wheel having a coating ofabrasive material thereon, said wheel driven by a motor to rotate, saidmotor and grinding wheel provided in a central housing and wherein thereare provided a plurality of tool holders, said tool holders movablebetween an out-of-use position and an in-use position with respect tothe said housing and, in the in-use position, providing a location for atool such that said tool is oriented in the appropriate position suchthat an edge and/or point of said tool can be sharpened in contact withsaid grinding wheel and wherein at least one of the tool holders isattached to the housing when in the in use and out of use positions andmoving between said positions.

A specific embodiment of the invention is now described wherein:—

FIG. 1 illustrates a perspective view of the sharpening apparatus withthe base according to one embodiment of the invention;

FIG. 2 illustrates the sharpening apparatus with the base removed with atool holder secured in the in-use position; and

FIG. 3 illustrates the base and lid of the sharpening apparatus.

With reference to the FIGS. 1 and 2 there is illustrated a sharpeningdevice 2 which is mounted on a base in the form of tray 4 and secured tothe same by screws 6. The tray 4 may also be fixed to a supportingsurface by screws 8.

The sharpening device 2 includes a housing 10 and a grinding wheel 12rotatably mounted a shaft of a motor (not shown) within the housing in asubstantially horizontal plane i.e. with a substantially verticalrotational axis. For safety, the majority of the wheel 12 is positionedwithin the housing 10, with the upper face and a portion of the sideface presented to the user. The housing 10 includes an angled recess ornotch 16 to allow tools such as a drill bit to be presented to the sideface of the wheel 12. When power is supplied to the motor by switchingthe on/off switch 18, the grinding wheel 12 rotates allowing any toolsapplied to the face or edge thereof to be sharpened due to the abrasivenature of the surface of the grinding wheel.

The grinding wheel 12 is secured to the motor within the housing 10 viaconventional means such as a nut or shaft 14. The grinding wheel 12 canthus be removed and reversed to allow both faces to be used or bereplaced with other forms of grinding and/or polishing wheels. A shaftlock can be provided to lock the shaft when the grinding wheel 12 isremoved.

The tray 4 and/or lid 11 as shown in FIG. 3 may also be provided with aseries of holes 30 for storing drill bits therein, and other toolaccessories. For example, a drill height guide 32 for collars 34 may beprovided, an additional grinding wheel may be mounted on the reverseface of the housing 10, and further storage may be provided forspanners, a water bath, cleaning brushes, safety glasses, and additionalgrinding or carborundum finishing stones. The lid can also be used as aguard for sparks and/or water when moved to an open or partially openposition as shown in FIG. 3 in bold lines and the lid can be moved to aclosed position for transport and/or storage in which the lid periphery52 contacts the base periphery 54.

The housing is illustrated with a tool holder 20 with a scissor guide 20and a tool holder 22 with a knife guide both connected thereto. The toolholders 20, 22 are hingedly connected to the lower part of the housing10 so they can each be pivoted upwards from the out-of-use position asshown in FIG. 1 to an in-use position as indicated by arrows 24. Thetool holders, when moved to an in use position preferably are angledbeyond vertical towards the housing 10 i.e have passed over centre ofthe pivot locations 25, 27 in the in-use position such that gravitybiases the tool holders 20, 22 towards the housing.

The housing 10 is provided with securing means in the form of arotatable catch 26 for each holder which passes through an aperture 28in the respective tool holders 20, 22, when the tool holder is moved toan in-use position. The catch can then be rotated to the lock the samein position.

The angled recess or notch 16 acts as another tool holder to allow acollar or bit holder 34 to be positioned therein, and hence positioningthe drill bit in the collar for sharpening against the grinding wheel12. Alternatively the drill bit or other tools can be positioned in therecess 16 directly.

An access port 46 is also provided to allow access to the grinding wheel12 to sharpen and/or tidy up other tools, especially those with flatnarrow edges such as screwdrivers.

Referring to FIG. 2, there is illustrated the sharpening apparatusmounted directly on a supporting surface 38 rather than a base or tray,and with one of the tool holders, in this case the one with the scissorguide 20 in an in-use position. The scissor guide is secured in positionby rotating the catch 26 which passes through an aperture in the scissorguide 20.

In use, for sharpening scissors a user holds one scissor blade along theangled edge 42 of the scissor guide, such that the edge of the firstscissor blade is in contact with the grinding wheel 12. With thegrinding wheel rotating as indicated by arrow 44, the first scissorblade is positioned on the face 42 at the correct angle to be sharpened.To allow the full length of the first blade to be sharpened, the scissorguide includes a recess or gap 40 in which the pivot part of thescissors sits. As scissor blades overlap to facilitate the shearingaction, without the recess the overlapping part of the second scissorblade would prevent the overlapped portion of the first scissor bladefrom contacting the grinding wheel.

Similarly, the tool holder 22 can be pivoted into an in-use positionsuch that the blade 48 placed thereon against the angled head 46 of thetool holder are held at the correct angle for sharpening against thegrinding wheel 12 when the tool holder is moved to the in-use positionwhich is possible even if the tool holder 20 remains in the in-useposition shown. FIG. 3 illustrates tool holder 22 in the in-use positionwith blade 49 being sharpened with the handle 50 being held by the user(not shown) and the lid 11 in position as a guard.

Protrusions 36 on the face of the tool holder 20, 22 maintain the toolholder in a position above the rotating grinding wheel 12 so the toolholder themselves are not worn by the same.

The location of the tool holders 20, 22 on the housing to be pivotallymovable between the out-of-use and in-use positions ensures that thesame can be accurately located with respect to the grinding wheel oneach occasion of use, especially given the over centre movement of thesame to the in-use position. This is important as the position of theblades when the respective holders with respect to the grinding wheelneeds to be correct in order to ensure that the grinding action on theblade edge actually acts to sharpen the same rather than damage theblade edge, which is what can occur if the blade edge is not correctlypositioned.

It will be appreciated by persons skilled in the art that the presentinvention also includes further additional modifications made to themethod which does not effect the overall functioning of the method, suchas the provision of decoration to provide improved aesthetic appearance,and/or the like.

1. Apparatus for the sharpening of a blade or cutting edge of a tool,said apparatus including a rotatable grinding wheel, a motor connectedto said grinding wheel, and a plurality of tool holders, at least one ofwhich is movable between an out of use position and an in-use positionwith respect to the grinding wheel and, in the in-use position, the saidat least one tool holder provides a location for a tool to be in theappropriate position such that an edge or point of said tool can besharpened in contact with said grinding wheel and wherein said at leastone tool holder is attached to a base and/or housing in which the motorand grinding wheel are provided, said connection retained in both in-useand out-of-use positions, and when moved between said positions. 2.Apparatus according to claim 1, wherein the said tool holder ispivotally movable between said in-use and out-of-use positions. 3.Apparatus according to claim 1 wherein securing means are mounted on thehousing to secure the tool holder in the in-use position with respect tothe housing.
 4. Apparatus according to claim 2 wherein when the said atleast one tool holder is moved to the in-use position, it moves overcentre of the pivotal connection of the tool holder thereby aiding theability of the tool holder to be kept in a fixed position with respectto the housing in the in-use position.
 5. Apparatus according to claim 1wherein a plurality of the tool holders are provided in a hingedpivotally movable relationship with the housing.
 6. Apparatus accordingto claim 5 wherein each of the tool holders is mounted with respect to adifferent face of said housing.
 7. Apparatus according to claim 5wherein each of said tool holders can be selectively moved independentlybetween in-use and out of use positions with respect to the grindingwheel.
 8. Apparatus according to claim 1 wherein at least one toolholder is provided in the form of an access port are provided on thehousing to allow a tool to be sharpened by to the grinding wheel byplacing the tool through said port.
 9. Apparatus according to claim 1wherein each tool holder is provided with location means for supportinga particular tool in the correct orientation with respect to thegrinding wheel.
 10. Apparatus according to claim 1 wherein adjustmentmeans are provided to allow the grinding wheel to be adjusted in heightwith respect to the housing.
 11. Apparatus according to claim 10 whereinthe adjustment means are located to adjust the height of the motorwithin the housing and thereby adjust the height of the grinding wheelconnected to the said motor.
 12. Apparatus according to claim 1 whereinthe housing is secured to a base, said base provided with storage meansfor storing any or any combination of tool holders and/or accessoriesfor use with the apparatus.
 13. Apparatus according to claim 12 whereinthe base includes an area for the collection of liquid to be used duringthe sharpening process.
 14. Apparatus according to claim 12 wherein thebase includes storage for additional grinding wheels.
 15. Apparatusaccording to claim 1 wherein the apparatus includes a carborundumfinishing stone.
 16. Apparatus according to claim 1 wherein the grindingwheel can be reversibly mounted with respect to a shaft leading from themotor.
 17. Apparatus according to claim 1 wherein the grinding wheel ismounted with respect to the motor so as to have a substantially verticalaxis of rotation.
 18. Apparatus according to claim 1 wherein the housingincludes a notched section to allow for the passage of a drill bittherethrough to be applied to the grinding wheel.
 19. Apparatusaccording to claim 18 wherein the drill bit is held in a chuck which ispositionable with respect to the housing.
 20. Apparatus according toclaim 1 wherein retention means are provided to allow the tool holdersto be retained in an out of use position.
 21. Apparatus according toclaim 1 wherein the apparatus includes a base on which the housing ismounted, and a lid which is engageable with the base and movable betweena closed storage position and a partially open guard position to protectthe user of the apparatus from sparks or other debris from the grindingprocess.